1. Field of the Invention
This invention relates to the field of hand tools for cutting plastic pipes and more particularly to the field of such hand tools with ratcheting mechanisms to progressively advance the cutting blade in a step-by-step manner through the pipe.
2. Discussion of the Background
Ratcheting cutting tools are widely used to cut plastic pipes (e.g., polyethylene) and in particular, hard plastic pipes including those made of polyvinylchloride (PVC). In use, such hand tools must be fairly strong and preferably easy to operate. However, most commercially available tools often have a relatively large number of moving parts and are normally somewhat complicated not only to make but also to use.
In many ratcheting cutters, the cutting blade is spring biased toward its open position and the tool has a release mechanism to let the spring automatically move the blade to its open position. These cutters further complicate the design of the cutter but offer advantages in time and ease over ones that must be manually opened after each cut in particular, manually operated ones often cannot easily be opened with one hand and require the operator either to use both of his hands to do so or to grip one handle and catch the other handle on his leg or something else. In close quarters such as in a hole installing irrigation pipes, there often is not room enough to grip both handles or otherwise manually manipulate the handles to open the cutter. Regardless, having to open the handles of such tools after each cut of a multiple cut operation can understandably be very time consuming and certainly less desirable than tools with spring arrangements to automatically open the cutter after each use.
Cutters with such spring arrangements typically include a release mechanism as indicated above wherein the blade of the completely ratcheted closed cutter can be released to return under the force of the spring to its open position. The cutting blade in this regard may be in its ratcheted closed position because it is the first cut of the day and the cutter was stored with the blade closed for safety or the user has just finished a cut and the closed blade is ready to be opened for the next one. Known cutters with spring arrangements and release mechanisms can be fairly involved. In many cases, there is a two or more step procedure or movement of various parts to release the blade to return to its open position. These arrangements can be for the most part both expensive to make and fairly difficult to use.
With this and other problems in mind, the present invention was developed. In it, a ratcheting cutting tool is provided that has a release mechanism that with one motion will disengage both the drive and catch pawls of the ratcheting arrangement in an easy and simple manner to permit the spring-biased blade to be automatically returned to its open position after each cut.